Semiempirical Methods for Propeller Noise Prediction

Abstract

Propellers are one of the main devices utilised to power aircraft, and interest in them has resurged due to recent developments in UAVs and eVTOLs. It is known that propellers are the main source of noise in aircraft, which is a major factor for annoyance, and manu- facturers continuously strive for lower noise levels due to increasingly stricter regulations and passenger comfort. In the conceptual phase of an aircraft, it is necessary to estimate its noise levels, and for the propellers, several prediction methods exist. The focus of this work is on semiempirical methods and an implementation of the SAE method to evaluate its accuracy when confronted with actual data. The results indicate that the SAE method has great accuracy in the far-field, with most of the estimated data being in the range of 3 dB of difference with the experimental data. However, in the near-field the results are worse, with errors as large as 20 dB when compared to experimental data. Since the SAE method relies on parameters commonly available at the start of a project and is inexpensive to employ, it should be used mainly in the conceptual phase of an aircraft.